• Home
  • Features
  • Pricing
  • Docs
  • Announcements
  • Sign In

randombit / botan / 15712221889

17 Jun 2025 10:50AM UTC coverage: 90.562% (-0.009%) from 90.571%
15712221889

push

github

web-flow
Merge pull request #4919 from randombit/jack/clang-tidy-headers-in-ci

Clang-tidy headers in CI

98791 of 109086 relevant lines covered (90.56%)

12355613.82 hits per line

Source File
Press 'n' to go to next uncovered line, 'b' for previous

98.34
/src/lib/utils/bitvector/bitvector.h
1
/*
2
 * An abstraction for an arbitrarily large bitvector that can
3
 * optionally use the secure_allocator. All bitwise accesses and all
4
 * constructors are implemented in constant time. Otherwise, only methods
5
 * with the "ct_" pre-fix run in constant time.
6
 *
7
 * (C) 2023-2024 Jack Lloyd
8
 * (C) 2023-2024 René Meusel, Rohde & Schwarz Cybersecurity
9
 *
10
 * Botan is released under the Simplified BSD License (see license.txt)
11
 */
12

13
#ifndef BOTAN_BIT_VECTOR_H_
14
#define BOTAN_BIT_VECTOR_H_
15

16
#include <botan/concepts.h>
17
#include <botan/exceptn.h>
18
#include <botan/mem_ops.h>
19
#include <botan/secmem.h>
20
#include <botan/strong_type.h>
21
#include <botan/internal/bit_ops.h>
22
#include <botan/internal/ct_utils.h>
23
#include <botan/internal/loadstor.h>
24
#include <botan/internal/stl_util.h>
25

26
#include <memory>
27
#include <optional>
28
#include <span>
29
#include <sstream>
30
#include <string>
31
#include <utility>
32
#include <vector>
33

34
namespace Botan {
35

36
template <template <typename> typename AllocatorT>
37
class bitvector_base;
38

39
template <typename T>
40
struct is_bitvector : std::false_type {};
41

42
template <template <typename> typename T>
43
struct is_bitvector<bitvector_base<T>> : std::true_type {};
44

45
template <typename T>
46
constexpr static bool is_bitvector_v = is_bitvector<T>::value;
47

48
template <typename T>
49
concept bitvectorish = is_bitvector_v<strong_type_wrapped_type<T>>;
50

51
namespace detail {
52

53
template <typename T0, typename... Ts>
54
struct first_type {
55
      using type = T0;
56
};
57

58
// get the first type from a parameter pack
59
// TODO: C++26 will bring Parameter Pack indexing:
60
//       using first_t = Ts...[0];
61
template <typename... Ts>
62
   requires(sizeof...(Ts) > 0)
63
using first_t = typename first_type<Ts...>::type;
64

65
// get the first object from a parameter pack
66
// TODO: C++26 will bring Parameter Pack indexing:
67
//       auto first = s...[0];
68
template <typename T0, typename... Ts>
69
constexpr static first_t<T0, Ts...> first(T0&& t, Ts&&...) {
70
   return std::forward<T0>(t);
71
}
72

73
template <typename OutT, typename>
74
using as = OutT;
75

76
template <typename FnT, std::unsigned_integral BlockT, typename... ParamTs>
77
using blockwise_processing_callback_return_type = std::invoke_result_t<FnT, as<BlockT, ParamTs>...>;
78

79
template <typename FnT, typename BlockT, typename... ParamTs>
80
concept is_blockwise_processing_callback_return_type =
81
   std::unsigned_integral<BlockT> &&
82
   (std::same_as<BlockT, blockwise_processing_callback_return_type<FnT, BlockT, ParamTs...>> ||
83
    std::same_as<bool, blockwise_processing_callback_return_type<FnT, BlockT, ParamTs...>> ||
84
    std::same_as<void, blockwise_processing_callback_return_type<FnT, BlockT, ParamTs...>>);
85

86
template <typename FnT, typename... ParamTs>
87
concept blockwise_processing_callback_without_mask =
88
   is_blockwise_processing_callback_return_type<FnT, uint8_t, ParamTs...> &&
89
   is_blockwise_processing_callback_return_type<FnT, uint16_t, ParamTs...> &&
90
   is_blockwise_processing_callback_return_type<FnT, uint32_t, ParamTs...> &&
91
   is_blockwise_processing_callback_return_type<FnT, uint64_t, ParamTs...>;
92

93
template <typename FnT, typename... ParamTs>
94
concept blockwise_processing_callback_with_mask =
95
   is_blockwise_processing_callback_return_type<FnT, uint8_t, ParamTs..., uint8_t /* mask */> &&
96
   is_blockwise_processing_callback_return_type<FnT, uint16_t, ParamTs..., uint16_t /* mask */> &&
97
   is_blockwise_processing_callback_return_type<FnT, uint32_t, ParamTs..., uint32_t /* mask */> &&
98
   is_blockwise_processing_callback_return_type<FnT, uint64_t, ParamTs..., uint64_t /* mask */>;
99

100
/**
101
 * Defines the callback constraints for the BitRangeOperator. For further
102
 * details, see bitvector_base::range_operation().
103
 */
104
template <typename FnT, typename... ParamTs>
105
concept blockwise_processing_callback = blockwise_processing_callback_with_mask<FnT, ParamTs...> ||
106
                                        blockwise_processing_callback_without_mask<FnT, ParamTs...>;
107

108
template <typename FnT, typename... ParamTs>
109
concept manipulating_blockwise_processing_callback =
110
   (blockwise_processing_callback_without_mask<FnT, ParamTs...> &&
111
    std::same_as<uint32_t, blockwise_processing_callback_return_type<FnT, uint32_t, ParamTs...>>) ||
112
   (blockwise_processing_callback_with_mask<FnT, ParamTs...> &&
113
    std::same_as<uint32_t, blockwise_processing_callback_return_type<FnT, uint32_t, ParamTs..., first_t<ParamTs...>>>);
114

115
template <typename FnT, typename... ParamTs>
116
concept predicate_blockwise_processing_callback =
117
   (blockwise_processing_callback_without_mask<FnT, ParamTs...> &&
118
    std::same_as<bool, blockwise_processing_callback_return_type<FnT, uint32_t, ParamTs...>>) ||
119
   (blockwise_processing_callback_with_mask<FnT, ParamTs...> &&
120
    std::same_as<bool, blockwise_processing_callback_return_type<FnT, uint32_t, ParamTs..., first_t<ParamTs...>>>);
121

122
template <typename T>
123
class bitvector_iterator {
124
   private:
125
      using size_type = typename T::size_type;
126

127
   public:
128
      using difference_type = std::make_signed_t<size_type>;
129
      using value_type = std::remove_const_t<decltype(std::declval<T>().at(0))>;
130
      using pointer = value_type*;
131
      using reference = value_type&;
132

133
      // TODO: technically, this could be a random access iterator
134
      using iterator_category = std::bidirectional_iterator_tag;
135

136
   public:
137
      bitvector_iterator() = default;
138
      ~bitvector_iterator() = default;
139

140
      bitvector_iterator(T* bitvector, size_t offset) : m_bitvector(bitvector) { update(offset); }
1,591✔
141

142
      bitvector_iterator(const bitvector_iterator& other) noexcept : m_bitvector(other.m_bitvector) {
2,002✔
143
         update(other.m_offset);
2,004✔
144
      }
145

146
      bitvector_iterator(bitvector_iterator&& other) noexcept : m_bitvector(other.m_bitvector) {
147
         update(other.m_offset);
148
      }
149

150
      bitvector_iterator& operator=(const bitvector_iterator& other) noexcept {
151
         if(this != &other) {
152
            m_bitvector = other.m_bitvector;
153
            update(other.m_offset);
154
         }
155
         return *this;
156
      }
157

158
      bitvector_iterator& operator=(bitvector_iterator&& other) noexcept {
159
         m_bitvector = other.m_bitvector;
160
         update(other.m_offset);
161
         return *this;
162
      }
163

164
      bitvector_iterator& operator++() noexcept {
252,074✔
165
         update(signed_offset() + 1);
504,173✔
166
         return *this;
167
      }
168

169
      bitvector_iterator operator++(int) noexcept {
6✔
170
         auto copy = *this;
6✔
171
         update(signed_offset() + 1);
12✔
172
         return copy;
6✔
173
      }
174

175
      bitvector_iterator& operator--() noexcept {
6✔
176
         update(signed_offset() - 1);
12✔
177
         return *this;
178
      }
179

180
      bitvector_iterator operator--(int) noexcept {
181
         auto copy = *this;
182
         update(signed_offset() - 1);
183
         return copy;
184
      }
185

186
      std::partial_ordering operator<=>(const bitvector_iterator& other) const noexcept {
187
         if(m_bitvector == other.m_bitvector) {
188
            return m_offset <=> other.m_offset;
189
         } else {
190
            return std::partial_ordering::unordered;
191
         }
192
      }
193

194
      bool operator==(const bitvector_iterator& other) const noexcept {
253,113✔
195
         return m_bitvector == other.m_bitvector && m_offset == other.m_offset;
252,578✔
196
      }
197

198
      reference operator*() const { return m_bitref.value(); }
2,223✔
199

200
      pointer operator->() const { return &(m_bitref.value()); }
262✔
201

202
   private:
203
      void update(size_type new_offset) {
529✔
204
         m_offset = new_offset;
1,026✔
205
         if(m_offset < m_bitvector->size()) {
1,506✔
206
            m_bitref.emplace((*m_bitvector)[m_offset]);
254,095✔
207
         } else {
208
            // end() iterator
209
            m_bitref.reset();
251,623✔
210
         }
211
      }
212

213
      difference_type signed_offset() const { return static_cast<difference_type>(m_offset); }
6✔
214

215
   private:
216
      T* m_bitvector;
217
      size_type m_offset;
218
      mutable std::optional<value_type> m_bitref;
219
};
220

221
}  // namespace detail
222

223
/**
224
 * An arbitrarily large bitvector with typical bit manipulation and convenient
225
 * bitwise access methods. Don't use `bitvector_base` directly, but the type
226
 * aliases::
227
 *
228
 *    * bitvector         - with a standard allocator
229
 *    * secure_bitvector  - with a secure allocator that auto-scrubs the memory
230
 */
231
template <template <typename> typename AllocatorT>
232
class bitvector_base final {
907,566✔
233
   public:
234
      using block_type = uint8_t;
235
      using size_type = size_t;
236
      using allocator_type = AllocatorT<block_type>;
237
      using value_type = block_type;
238
      using iterator = detail::bitvector_iterator<bitvector_base<AllocatorT>>;
239
      using const_iterator = detail::bitvector_iterator<const bitvector_base<AllocatorT>>;
240

241
      static constexpr size_type block_size_bytes = sizeof(block_type);
242
      static constexpr size_type block_size_bits = block_size_bytes * 8;
243
      static constexpr bool uses_secure_allocator = std::is_same_v<allocator_type, secure_allocator<block_type>>;
244

245
   private:
246
      template <template <typename> typename FriendAllocatorT>
247
      friend class bitvector_base;
248

249
      static constexpr block_type one = block_type(1);
250

251
      static constexpr size_type block_offset_shift = size_type(3) + ceil_log2(block_size_bytes);
252
      static constexpr size_type block_index_mask = (one << block_offset_shift) - 1;
253

254
      static constexpr size_type block_index(size_type pos) { return pos >> block_offset_shift; }
21,157,507✔
255

256
      static constexpr size_type block_offset(size_type pos) { return pos & block_index_mask; }
1,166,177,472✔
257

258
   private:
259
      /**
260
       * Internal helper to wrap a single bit in the bitvector and provide
261
       * certain convenience access methods.
262
       */
263
      template <typename BlockT>
264
         requires std::same_as<block_type, std::remove_cv_t<BlockT>>
265
      class bitref_base {
266
         private:
267
            friend class bitvector_base<AllocatorT>;
268

269
            constexpr bitref_base(std::span<BlockT> blocks, size_type pos) noexcept :
1,556,738,230✔
270
                  m_block(blocks[block_index(pos)]), m_mask(one << block_offset(pos)) {}
1,556,738,230✔
271

272
         public:
273
            bitref_base() = delete;
274
            bitref_base(const bitref_base&) noexcept = default;
275
            bitref_base(bitref_base&&) noexcept = default;
276
            bitref_base& operator=(const bitref_base&) = delete;
277
            bitref_base& operator=(bitref_base&&) = delete;
278

279
            ~bitref_base() = default;
280

281
         public:
282
            constexpr operator bool() const noexcept { return is_set(); }
13,383,147✔
283

284
            constexpr bool is_set() const noexcept { return (m_block & m_mask) > 0; }
13,331,978✔
285

286
            template <std::integral T>
287
            constexpr T as() const noexcept {
288,057✔
288
               return static_cast<T>(is_set());
94,674✔
289
            }
290

291
            constexpr CT::Choice as_choice() const noexcept {
389,183,165✔
292
               return CT::Choice::from_int(static_cast<BlockT>(m_block & m_mask));
389,183,165✔
293
            }
294

295
         protected:
296
            BlockT& m_block;  // NOLINT(*-non-private-member-variable*)
297
            BlockT m_mask;    // NOLINT(*-non-private-member-variable*)
298
      };
299

300
   public:
301
      /**
302
       * Wraps a constant reference into the bitvector. Bit can be accessed
303
       * but not modified.
304
       */
305
      template <typename BlockT>
306
      class bitref final : public bitref_base<BlockT> {
307
         public:
308
            using bitref_base<BlockT>::bitref_base;
12,641,313✔
309
      };
310

311
      /**
312
       * Wraps a modifiable reference into the bitvector. Bit may be accessed
313
       * and modified (e.g. flipped or XOR'ed).
314
       *
315
       * Constant-time operations are used for the bit manipulations. The
316
       * location of the bit in the bit vector may be leaked, though.
317
       */
318
      template <typename BlockT>
319
         requires(!std::is_const_v<BlockT>)
320
      class bitref<BlockT> : public bitref_base<BlockT> {
321
         public:
322
            using bitref_base<BlockT>::bitref_base;
1,153,794,564✔
323

324
            ~bitref() = default;
325
            bitref(const bitref&) noexcept = default;
326
            bitref(bitref&&) noexcept = default;
327

328
            constexpr bitref& set() noexcept {
361✔
329
               this->m_block |= this->m_mask;
26✔
330
               return *this;
250✔
331
            }
332

333
            constexpr bitref& unset() noexcept {
7✔
334
               this->m_block &= ~this->m_mask;
1✔
335
               return *this;
336
            }
337

338
            constexpr bitref& flip() noexcept {
16✔
339
               this->m_block ^= this->m_mask;
7✔
340
               return *this;
341
            }
342

343
            // NOLINTBEGIN
344

345
            constexpr bitref& operator=(bool bit) noexcept {
1,153,561,268✔
346
               this->m_block =
1,153,561,268✔
347
                  CT::Mask<BlockT>::expand(bit).select(this->m_mask | this->m_block, this->m_block & ~this->m_mask);
1,153,561,268✔
348
               return *this;
1,153,561,268✔
349
            }
350

351
            constexpr bitref& operator=(const bitref& bit) noexcept { return *this = bit.is_set(); }
352

353
            constexpr bitref& operator=(bitref&& bit) noexcept { return *this = bit.is_set(); }
354

355
            // NOLINTEND
356

357
            constexpr bitref& operator&=(bool other) noexcept {
4✔
358
               this->m_block &= ~CT::Mask<BlockT>::expand(other).if_not_set_return(this->m_mask);
4✔
359
               return *this;
360
            }
361

362
            constexpr bitref& operator|=(bool other) noexcept {
4✔
363
               this->m_block |= CT::Mask<BlockT>::expand(other).if_set_return(this->m_mask);
4✔
364
               return *this;
365
            }
366

367
            constexpr bitref& operator^=(bool other) noexcept {
70,599✔
368
               this->m_block ^= CT::Mask<BlockT>::expand(other).if_set_return(this->m_mask);
70,599✔
369
               return *this;
370
            }
371
      };
372

373
   public:
374
      bitvector_base() : m_bits(0) {}
58✔
375

376
      bitvector_base(size_type bits) : m_bits(bits), m_blocks(ceil_toblocks(bits)) {}
238,722✔
377

378
      /**
379
       * Initialize the bitvector from a byte-array. Bits are taken byte-wise
380
       * from least significant to most significant. Example::
381
       *
382
       *    bitvector[0] -> LSB(Byte[0])
383
       *    bitvector[1] -> LSB+1(Byte[0])
384
       *    ...
385
       *    bitvector[8] -> LSB(Byte[1])
386
       *
387
       * @param bytes The byte vector to be loaded
388
       * @param bits  The number of bits to be loaded. This must not be more
389
       *              than the number of bytes in @p bytes.
390
       */
391
      bitvector_base(std::span<const uint8_t> bytes, std::optional<size_type> bits = std::nullopt) {
72,463✔
392
         from_bytes(bytes, bits);
72,463✔
393
      }
72,463✔
394

395
      bitvector_base(std::initializer_list<block_type> blocks, std::optional<size_type> bits = std::nullopt) :
167✔
396
            m_bits(bits.value_or(blocks.size() * block_size_bits)), m_blocks(blocks.begin(), blocks.end()) {}
167✔
397

398
      bool empty() const { return m_bits == 0; }
6✔
399

400
      size_type size() const { return m_bits; }
8,455,885✔
401

402
      /**
403
       * @returns true iff the number of 1-bits in this is odd, false otherwise (constant time)
404
       */
405
      CT::Choice has_odd_hamming_weight() const {
70,599✔
406
         uint64_t acc = 0;
70,599✔
407
         full_range_operation([&](std::unsigned_integral auto block) { acc ^= block; }, *this);
70,599✔
408

409
         for(size_t i = (sizeof(acc) * 8) >> 1; i > 0; i >>= 1) {
494,193✔
410
            acc ^= acc >> i;
423,594✔
411
         }
412

413
         return CT::Choice::from_int(acc & one);
70,599✔
414
      }
415

416
      /**
417
       * Counts the number of 1-bits in the bitvector in constant time.
418
       * @returns the "population count" (or hamming weight) of the bitvector
419
       */
420
      size_type hamming_weight() const {
125✔
421
         size_type acc = 0;
125✔
422
         full_range_operation([&](std::unsigned_integral auto block) { acc += ct_popcount(block); }, *this);
63✔
423
         return acc;
108✔
424
      }
425

426
      /**
427
       * @returns copies this bitvector into a new bitvector of type @p OutT
428
       */
429
      template <bitvectorish OutT>
430
      OutT as() const {
112✔
431
         return subvector<OutT>(0, size());
194✔
432
      }
433

434
      /**
435
       * @returns true if @p other contains the same bit pattern as this
436
       */
437
      template <bitvectorish OtherT>
438
      bool equals_vartime(const OtherT& other) const noexcept {
8✔
439
         return size() == other.size() &&
10✔
440
                full_range_operation([]<std::unsigned_integral BlockT>(BlockT lhs, BlockT rhs) { return lhs == rhs; },
10✔
441
                                     *this,
442
                                     unwrap_strong_type(other));
443
      }
444

445
      /**
446
       * @returns true if @p other contains the same bit pattern as this
447
       */
448
      template <bitvectorish OtherT>
449
      bool equals(const OtherT& other) const noexcept {
47✔
450
         return (*this ^ other).none();
47✔
451
      }
452

453
      /// @name Serialization
454
      /// @{
455

456
      /**
457
       * Re-initialize the bitvector with the given bytes. See the respective
458
       * constructor for details. This should be used only when trying to save
459
       * allocations. Otherwise, use the constructor.
460
       *
461
       * @param bytes  the byte range to load bits from
462
       * @param bits   (optional) if not all @p bytes should be loaded in full
463
       */
464
      void from_bytes(std::span<const uint8_t> bytes, std::optional<size_type> bits = std::nullopt) {
72,463✔
465
         m_bits = bits.value_or(bytes.size_bytes() * 8);
72,463✔
466
         BOTAN_ARG_CHECK(m_bits <= bytes.size_bytes() * 8, "not enough data to load so many bits");
72,463✔
467
         resize(m_bits);
72,463✔
468

469
         // load as much aligned data as possible
470
         const auto verbatim_blocks = m_bits / block_size_bits;
72,463✔
471
         const auto verbatim_bytes = verbatim_blocks * block_size_bytes;
72,463✔
472
         if(verbatim_blocks > 0) {
72,463✔
473
            typecast_copy(std::span{m_blocks}.first(verbatim_blocks), bytes.first(verbatim_bytes));
72,462✔
474
         }
475

476
         // load remaining unaligned data
477
         for(size_type i = verbatim_bytes * 8; i < m_bits; ++i) {
165,327✔
478
            ref(i) = ((bytes[i >> 3] & (uint8_t(1) << (i & 7))) != 0);
92,864✔
479
         }
480
      }
72,463✔
481

482
      /**
483
       * Renders the bitvector into a byte array. By default, this will use
484
       * `std::vector<uint8_t>` or `Botan::secure_vector<uint8_t>`, depending on
485
       * the allocator used by the bitvector. The rendering is compatible with
486
       * the bit layout explained in the respective constructor.
487
       */
488
      template <concepts::resizable_byte_buffer OutT =
489
                   std::conditional_t<uses_secure_allocator, secure_vector<uint8_t>, std::vector<uint8_t>>>
490
      OutT to_bytes() const {
297✔
491
         OutT out(ceil_tobytes(m_bits));
297✔
492
         to_bytes(out);
297✔
493
         return out;
297✔
494
      }
×
495

496
      /**
497
       * Renders the bitvector into a properly sized byte range.
498
       *
499
       * @param out  a byte range that has a length of at least `ceil_tobytes(size())`.
500
       */
501
      void to_bytes(std::span<uint8_t> out) const {
119,277✔
502
         const auto bytes_needed = ceil_tobytes(m_bits);
119,277✔
503
         BOTAN_ARG_CHECK(bytes_needed <= out.size_bytes(), "Not enough space to render bitvector");
119,277✔
504

505
         // copy as much aligned data as possible
506
         const auto verbatim_blocks = m_bits / block_size_bits;
119,277✔
507
         const auto verbatim_bytes = verbatim_blocks * block_size_bytes;
119,277✔
508
         if(verbatim_blocks > 0) {
119,277✔
509
            typecast_copy(out.first(verbatim_bytes), std::span{m_blocks}.first(verbatim_blocks));
119,274✔
510
         }
511

512
         // copy remaining unaligned data
513
         clear_mem(out.subspan(verbatim_bytes));
119,277✔
514
         for(size_type i = verbatim_bytes * 8; i < m_bits; ++i) {
312,696✔
515
            out[i >> 3] |= ref(i).template as<uint8_t>() << (i & 7);
193,419✔
516
         }
517
      }
119,277✔
518

519
      /**
520
       * Renders this bitvector into a sequence of "0"s and "1"s.
521
       * This is meant for debugging purposes and is not efficient.
522
       */
523
      std::string to_string() const {
1✔
524
         std::stringstream ss;
1✔
525
         for(size_type i = 0; i < size(); ++i) {
6✔
526
            ss << ref(i);
5✔
527
         }
528
         return ss.str();
1✔
529
      }
1✔
530

531
      /// @}
532

533
      /// @name Capacity Accessors and Modifiers
534
      /// @{
535

536
      size_type capacity() const { return m_blocks.capacity() * block_size_bits; }
6✔
537

538
      void reserve(size_type bits) { m_blocks.reserve(ceil_toblocks(bits)); }
53✔
539

540
      void resize(size_type bits) {
400,066✔
541
         const auto new_number_of_blocks = ceil_toblocks(bits);
400,066✔
542
         if(new_number_of_blocks != m_blocks.size()) {
400,066✔
543
            m_blocks.resize(new_number_of_blocks);
113,465✔
544
         }
545

546
         m_bits = bits;
400,066✔
547
         zero_unused_bits();
400,066✔
548
      }
400,059✔
549

550
      void push_back(bool bit) {
327,535✔
551
         const auto i = size();
327,535✔
552
         resize(i + 1);
327,535✔
553
         ref(i) = bit;
655,070✔
554
      }
327,535✔
555

556
      void pop_back() {
9✔
557
         if(!empty()) {
9✔
558
            resize(size() - 1);
9✔
559
         }
560
      }
561

562
      /// @}
563

564
      /// @name Bitwise and Global Accessors and Modifiers
565
      /// @{
566

567
      auto at(size_type pos) {
397,992,828✔
568
         check_offset(pos);
397,992,824✔
569
         return ref(pos);
397,992,551✔
570
      }
571

572
      // TODO C++23: deducing this
573
      auto at(size_type pos) const {
757,441✔
574
         check_offset(pos);
757,440✔
575
         return ref(pos);
757,440✔
576
      }
577

578
      auto front() { return ref(0); }
2✔
579

580
      // TODO C++23: deducing this
581
      auto front() const { return ref(0); }
582

583
      auto back() { return ref(size() - 1); }
5✔
584

585
      // TODO C++23: deducing this
586
      auto back() const { return ref(size() - 1); }
587

588
      /**
589
       * Sets the bit at position @p pos.
590
       * @throws Botan::Invalid_Argument if @p pos is out of range
591
       */
592
      bitvector_base& set(size_type pos) {
86✔
593
         check_offset(pos);
85✔
594
         ref(pos).set();
51✔
595
         return *this;
35✔
596
      }
597

598
      /**
599
       * Sets all currently allocated bits.
600
       */
601
      bitvector_base& set() {
2✔
602
         full_range_operation(
2✔
603
            [](std::unsigned_integral auto block) -> decltype(block) {
2✔
604
               return static_cast<decltype(block)>(~static_cast<decltype(block)>(0));
605
            },
606
            *this);
607
         zero_unused_bits();
2✔
608
         return *this;
2✔
609
      }
610

611
      /**
612
       * Unsets the bit at position @p pos.
613
       * @throws Botan::Invalid_Argument if @p pos is out of range
614
       */
615
      bitvector_base& unset(size_type pos) {
7✔
616
         check_offset(pos);
6✔
617
         ref(pos).unset();
6✔
618
         return *this;
6✔
619
      }
620

621
      /**
622
       * Unsets all currently allocated bits.
623
       */
624
      bitvector_base& unset() {
4✔
625
         full_range_operation(
4✔
626
            [](std::unsigned_integral auto block) -> decltype(block) { return static_cast<decltype(block)>(0); },
4✔
627
            *this);
628
         return *this;
629
      }
630

631
      /**
632
       * Flips the bit at position @p pos.
633
       * @throws Botan::Invalid_Argument if @p pos is out of range
634
       */
635
      bitvector_base& flip(size_type pos) {
10✔
636
         check_offset(pos);
9✔
637
         ref(pos).flip();
9✔
638
         return *this;
9✔
639
      }
640

641
      /**
642
       * Flips all currently allocated bits.
643
       */
644
      bitvector_base& flip() {
5✔
645
         full_range_operation([](std::unsigned_integral auto block) -> decltype(block) { return ~block; }, *this);
5✔
646
         zero_unused_bits();
5✔
647
         return *this;
5✔
648
      }
649

650
      /**
651
       * @returns true iff no bit is set
652
       */
653
      bool none_vartime() const {
13✔
654
         return full_range_operation([](std::unsigned_integral auto block) { return block == 0; }, *this);
6✔
655
      }
656

657
      /**
658
       * @returns true iff no bit is set in constant time
659
       */
660
      bool none() const { return hamming_weight() == 0; }
52✔
661

662
      /**
663
       * @returns true iff at least one bit is set
664
       */
665
      bool any_vartime() const { return !none_vartime(); }
7✔
666

667
      /**
668
       * @returns true iff at least one bit is set in constant time
669
       */
670
      bool any() const { return !none(); }
5✔
671

672
      /**
673
       * @returns true iff all bits are set
674
       */
675
      bool all_vartime() const {
7✔
676
         return full_range_operation(
7✔
677
            []<std::unsigned_integral BlockT>(BlockT block, BlockT mask) { return block == mask; }, *this);
6✔
678
      }
679

680
      /**
681
       * @returns true iff all bits are set in constant time
682
       */
683
      bool all() const { return hamming_weight() == m_bits; }
5✔
684

685
      auto operator[](size_type pos) { return ref(pos); }
1,144,926,147✔
686

687
      // TODO C++23: deducing this
688
      auto operator[](size_type pos) const { return ref(pos); }
12,447,889✔
689

690
      /// @}
691

692
      /// @name Subvectors
693
      /// @{
694

695
      /**
696
       * Creates a new bitvector with a subsection of this bitvector starting at
697
       * @p pos copying exactly @p length bits.
698
       */
699
      template <bitvectorish OutT = bitvector_base<AllocatorT>>
700
      auto subvector(size_type pos, std::optional<size_type> length = std::nullopt) const {
119,162✔
701
         size_type bitlen = length.value_or(size() - pos);
119,162✔
702
         BOTAN_ARG_CHECK(pos + bitlen <= size(), "Not enough bits to copy");
119,162✔
703

704
         OutT newvector(bitlen);
119,158✔
705

706
         // Handle bitvectors that are wrapped in strong types
707
         auto& newvector_unwrapped = unwrap_strong_type(newvector);
119,158✔
708

709
         if(bitlen > 0) {
119,158✔
710
            if(pos % 8 == 0) {
119,155✔
711
               copy_mem(
80,461✔
712
                  newvector_unwrapped.m_blocks,
50✔
713
                  std::span{m_blocks}.subspan(block_index(pos), block_index(pos + bitlen - 1) - block_index(pos) + 1));
80,461✔
714
            } else {
715
               BitRangeOperator<const bitvector_base<AllocatorT>, BitRangeAlignment::no_alignment> from_op(
38,694✔
716
                  *this, pos, bitlen);
717
               BitRangeOperator<strong_type_wrapped_type<OutT>> to_op(
38,694✔
718
                  unwrap_strong_type(newvector_unwrapped), 0, bitlen);
719
               range_operation([](auto /* to */, auto from) { return from; }, to_op, from_op);
38,694✔
720
            }
721

722
            newvector_unwrapped.zero_unused_bits();
119,158✔
723
         }
724

725
         return newvector;
119,158✔
726
      }
×
727

728
      /**
729
       * Extracts a subvector of bits as an unsigned integral type @p OutT
730
       * starting from bit @p pos and copying exactly sizeof(OutT)*8 bits.
731
       *
732
       * Hint: The bits are in big-endian order, i.e. the least significant bit
733
       *       is the 0th bit and the most significant bit it the n-th. Hence,
734
       *       addressing the bits with bitwise operations is done like so:
735
       *       bool bit = (out_int >> pos) & 1;
736
       */
737
      template <typename OutT>
738
         requires(std::unsigned_integral<strong_type_wrapped_type<OutT>> &&
739
                  !std::same_as<bool, strong_type_wrapped_type<OutT>>)
740
      OutT subvector(size_type pos) const {
65,744✔
741
         using result_t = strong_type_wrapped_type<OutT>;
742
         constexpr size_t bits = sizeof(result_t) * 8;
65,744✔
743
         BOTAN_ARG_CHECK(pos + bits <= size(), "Not enough bits to copy");
65,744✔
744
         result_t out = 0;
65,740✔
745

746
         if(pos % 8 == 0) {
65,740✔
747
            out = load_le<result_t>(std::span{m_blocks}.subspan(block_index(pos)).template first<sizeof(result_t)>());
39,432✔
748
         } else {
749
            BitRangeOperator<const bitvector_base<AllocatorT>, BitRangeAlignment::no_alignment> op(*this, pos, bits);
26,308✔
750
            range_operation(
26,308✔
751
               [&](std::unsigned_integral auto integer) {
26,308✔
752
                  if constexpr(std::same_as<result_t, decltype(integer)>) {
753
                     out = integer;
26,308✔
754
                  }
755
               },
756
               op);
757
         }
758

759
         return wrap_strong_type<OutT>(out);
65,740✔
760
      }
761

762
      /**
763
       * Replaces a subvector of bits with the bits of another bitvector @p value
764
       * starting at bit @p pos. The number of bits to replace is determined by
765
       * the size of @p value.
766
       *
767
       * @note This is currently supported for byte-aligned @p pos only.
768
       *
769
       * @throws Not_Implemented when called with @p pos not divisible by 8.
770
       *
771
       * @param pos    the position to start replacing bits
772
       * @param value  the bitvector to copy bits from
773
       */
774
      template <typename InT>
775
         requires(std::unsigned_integral<strong_type_wrapped_type<InT>> && !std::same_as<bool, InT>)
776
      void subvector_replace(size_type pos, InT value) {
65,751✔
777
         using in_t = strong_type_wrapped_type<InT>;
778
         constexpr size_t bits = sizeof(in_t) * 8;
65,751✔
779
         BOTAN_ARG_CHECK(pos + bits <= size(), "Not enough bits to replace");
65,751✔
780

781
         if(pos % 8 == 0) {
65,747✔
782
            store_le(std::span{m_blocks}.subspan(block_index(pos)).template first<sizeof(in_t)>(),
39,434✔
783
                     unwrap_strong_type(value));
784
         } else {
785
            BitRangeOperator<bitvector_base<AllocatorT>, BitRangeAlignment::no_alignment> op(*this, pos, bits);
26,313✔
786
            range_operation(
26,313✔
787
               [&]<std::unsigned_integral BlockT>(BlockT block) -> BlockT {
26,313✔
788
                  if constexpr(std::same_as<in_t, BlockT>) {
789
                     return unwrap_strong_type(value);
26,313✔
790
                  } else {
791
                     // This should never be reached. BOTAN_ASSERT_UNREACHABLE()
792
                     // caused warning "unreachable code" on MSVC, though. You
793
                     // don't say!
794
                     //
795
                     // Returning the given block back, is the most reasonable
796
                     // thing to do in this case, though.
797
                     return block;
798
                  }
799
               },
800
               op);
801
         }
802
      }
65,747✔
803

804
      /// @}
805

806
      /// @name Operators
807
      ///
808
      /// @{
809

810
      auto operator~() {
1✔
811
         auto newbv = *this;
1✔
812
         newbv.flip();
1✔
813
         return newbv;
1✔
814
      }
×
815

816
      template <bitvectorish OtherT>
817
      auto& operator|=(const OtherT& other) {
5✔
818
         full_range_operation([]<std::unsigned_integral BlockT>(BlockT lhs, BlockT rhs) -> BlockT { return lhs | rhs; },
2✔
819
                              *this,
820
                              unwrap_strong_type(other));
821
         return *this;
822
      }
823

824
      template <bitvectorish OtherT>
825
      auto& operator&=(const OtherT& other) {
70,600✔
826
         full_range_operation([]<std::unsigned_integral BlockT>(BlockT lhs, BlockT rhs) -> BlockT { return lhs & rhs; },
70,597✔
827
                              *this,
828
                              unwrap_strong_type(other));
829
         return *this;
830
      }
831

832
      template <bitvectorish OtherT>
833
      auto& operator^=(const OtherT& other) {
54✔
834
         full_range_operation([]<std::unsigned_integral BlockT>(BlockT lhs, BlockT rhs) -> BlockT { return lhs ^ rhs; },
136✔
835
                              *this,
836
                              unwrap_strong_type(other));
837
         return *this;
838
      }
839

840
      /// @}
841

842
      /// @name Constant Time Operations
843
      ///
844
      /// @{
845

846
      /**
847
       * Implements::
848
       *
849
       *    if(condition) {
850
       *       *this ^= other;
851
       *    }
852
       *
853
       * omitting runtime dependence on any of the parameters.
854
       */
855
      template <bitvectorish OtherT>
856
      void ct_conditional_xor(CT::Choice condition, const OtherT& other) {
393,335,683✔
857
         BOTAN_ASSERT_NOMSG(m_bits == other.m_bits);
393,335,683✔
858
         BOTAN_ASSERT_NOMSG(m_blocks.size() == other.m_blocks.size());
393,335,683✔
859

860
         auto maybe_xor = overloaded{
861
            [m = CT::Mask<uint64_t>::from_choice(condition)](uint64_t lhs, uint64_t rhs) -> uint64_t {
924,857,225✔
862
               return lhs ^ m.if_set_return(rhs);
2,147,483,647✔
863
            },
864
            [m = CT::Mask<uint32_t>::from_choice(condition)](uint32_t lhs, uint32_t rhs) -> uint32_t {
646,629,514✔
865
               return lhs ^ m.if_set_return(rhs);
253,293,831✔
866
            },
867
            [m = CT::Mask<uint16_t>::from_choice(condition)](uint16_t lhs, uint16_t rhs) -> uint16_t {
500,945,009✔
868
               return lhs ^ m.if_set_return(rhs);
107,609,326✔
869
            },
870
            [m = CT::Mask<uint8_t>::from_choice(condition)](uint8_t lhs, uint8_t rhs) -> uint8_t {
393,335,689✔
871
               return lhs ^ m.if_set_return(rhs);
6✔
872
            },
873
         };
874

875
         full_range_operation(maybe_xor, *this, unwrap_strong_type(other));
393,335,683✔
876
      }
393,335,683✔
877

878
      constexpr void _const_time_poison() const { CT::poison(m_blocks); }
51✔
879

880
      constexpr void _const_time_unpoison() const { CT::unpoison(m_blocks); }
86✔
881

882
      /// @}
883

884
      /// @name Iterators
885
      ///
886
      /// @{
887

888
      iterator begin() noexcept { return iterator(this, 0); }
1,078✔
889

890
      const_iterator begin() const noexcept { return const_iterator(this, 0); }
891

892
      const_iterator cbegin() const noexcept { return const_iterator(this, 0); }
10✔
893

894
      iterator end() noexcept { return iterator(this, size()); }
546✔
895

896
      const_iterator end() const noexcept { return const_iterator(this, size()); }
897

898
      const_iterator cend() noexcept { return const_iterator(this, size()); }
8✔
899

900
      /// @}
901

902
   private:
903
      void check_offset(size_type pos) const {
398,750,000✔
904
         // BOTAN_ASSERT_NOMSG(!CT::is_poisoned(&m_bits, sizeof(m_bits)));
905
         // BOTAN_ASSERT_NOMSG(!CT::is_poisoned(&pos, sizeof(pos)));
906
         BOTAN_ARG_CHECK(pos < m_bits, "Out of range");
398,750,338✔
907
      }
908

909
      void zero_unused_bits() {
519,221✔
910
         const auto first_unused_bit = size();
517,486✔
911

912
         // Zero out any unused bits in the last block
913
         if(first_unused_bit % block_size_bits != 0) {
519,221✔
914
            const block_type mask = (one << block_offset(first_unused_bit)) - one;
343,916✔
915
            m_blocks[block_index(first_unused_bit)] &= mask;
343,916✔
916
         }
917
      }
918

919
      static constexpr size_type ceil_toblocks(size_type bits) {
517,834✔
920
         return (bits + block_size_bits - 1) / block_size_bits;
519,536✔
921
      }
922

923
      auto ref(size_type pos) const { return bitref<const block_type>(m_blocks, pos); }
12,641,313✔
924

925
      auto ref(size_type pos) { return bitref<block_type>(m_blocks, pos); }
1,153,794,564✔
926

927
   private:
928
      enum class BitRangeAlignment : uint8_t { byte_aligned, no_alignment };
929

930
      /**
931
       * Helper construction to implement bit range operations on the bitvector.
932
       * It basically implements an iterator to read and write blocks of bits
933
       * from the underlying bitvector. Where "blocks of bits" are unsigned
934
       * integers of varying bit lengths.
935
       *
936
       * If the iteration starts at a byte boundary in the underlying bitvector,
937
       * this applies certain optimizations (i.e. loading blocks of bits straight
938
       * from the underlying byte buffer). The optimizations are enabled at
939
       * compile time (with the template parameter `alignment`).
940
       */
941
      template <typename BitvectorT, auto alignment = BitRangeAlignment::byte_aligned>
942
         requires is_bitvector_v<std::remove_cvref_t<BitvectorT>>
943
      class BitRangeOperator {
944
         private:
945
            constexpr static bool is_const() { return std::is_const_v<BitvectorT>; }
946

947
            struct UnalignedDataHelper {
948
                  const uint8_t padding_bits;
949
                  const uint8_t bits_to_byte_alignment;
950
            };
951

952
         public:
953
            BitRangeOperator(BitvectorT& source, size_type start_bitoffset, size_type bitlength) :
787,013,464✔
954
                  m_source(source),
787,013,464✔
955
                  m_start_bitoffset(start_bitoffset),
787,013,464✔
956
                  m_bitlength(bitlength),
787,013,464✔
957
                  m_unaligned_helper({.padding_bits = static_cast<uint8_t>(start_bitoffset % 8),
787,013,464✔
958
                                      .bits_to_byte_alignment = static_cast<uint8_t>(8 - (start_bitoffset % 8))}),
787,013,464✔
959
                  m_read_bitpos(start_bitoffset),
787,013,464✔
960
                  m_write_bitpos(start_bitoffset) {
787,013,464✔
961
               BOTAN_ASSERT(is_byte_aligned() == (m_start_bitoffset % 8 == 0), "byte alignment guarantee");
787,013,464✔
962
               BOTAN_ASSERT(m_source.size() >= m_start_bitoffset + m_bitlength, "enough bytes in underlying source");
787,013,464✔
963
            }
787,013,464✔
964

965
            BitRangeOperator(BitvectorT& source) : BitRangeOperator(source, 0, source.size()) {}
786,883,455✔
966

967
            static constexpr bool is_byte_aligned() { return alignment == BitRangeAlignment::byte_aligned; }
968

969
            /**
970
             * @returns the overall number of bits to be iterated with this operator
971
             */
972
            size_type size() const { return m_bitlength; }
393,445,044✔
973

974
            /**
975
             * @returns the number of bits not yet read from this operator
976
             */
977
            size_type bits_to_read() const { return m_bitlength - m_read_bitpos + m_start_bitoffset; }
1,581,036,249✔
978

979
            /**
980
             * @returns the number of bits still to be written into this operator
981
             */
982
            size_type bits_to_write() const { return m_bitlength - m_write_bitpos + m_start_bitoffset; }
3,398,317✔
983

984
            /**
985
             * Loads the next block of bits from the underlying bitvector. No
986
             * bounds checks are performed. The caller can define the size of
987
             * the resulting unsigned integer block.
988
             */
989
            template <std::unsigned_integral BlockT>
990
            BlockT load_next() const {
6,762,606✔
991
               constexpr size_type block_size = sizeof(BlockT);
6,762,606✔
992
               constexpr size_type block_bits = block_size * 8;
6,762,606✔
993
               const auto bits_remaining = bits_to_read();
6,762,606✔
994

995
               BlockT result_block = 0;
6,762,606✔
996
               if constexpr(is_byte_aligned()) {
997
                  result_block = load_le(m_source.as_byte_span().subspan(read_bytepos()).template first<block_size>());
3,382,892✔
998
               } else {
999
                  const size_type byte_pos = read_bytepos();
3,379,714✔
1000
                  const size_type bits_to_collect = std::min(block_bits, bits_to_read());
6,759,428✔
1001

1002
                  const uint8_t first_byte = m_source.as_byte_span()[byte_pos];
3,379,714✔
1003

1004
                  // Initialize the left-most bits from the first byte.
1005
                  result_block = BlockT(first_byte) >> m_unaligned_helper.padding_bits;
3,379,714✔
1006

1007
                  // If more bits are needed, we pull them from the remaining bytes.
1008
                  if(m_unaligned_helper.bits_to_byte_alignment < bits_to_collect) {
3,379,714✔
1009
                     const BlockT block =
1010
                        load_le(m_source.as_byte_span().subspan(byte_pos + 1).template first<block_size>());
6,682,042✔
1011
                     result_block |= block << m_unaligned_helper.bits_to_byte_alignment;
3,341,024✔
1012
                  }
1013
               }
1014

1015
               m_read_bitpos += std::min(block_bits, bits_remaining);
6,762,606✔
1016
               return result_block;
6,668,117✔
1017
            }
1018

1019
            /**
1020
             * Stores the next block of bits into the underlying bitvector.
1021
             * No bounds checks are performed. Storing bit blocks that are not
1022
             * aligned at a byte-boundary in the underlying bitvector is
1023
             * currently not implemented.
1024
             */
1025
            template <std::unsigned_integral BlockT>
1026
               requires(!is_const())
1027
            void store_next(BlockT block) {
3,372,004✔
1028
               constexpr size_type block_size = sizeof(BlockT);
3,372,004✔
1029
               constexpr size_type block_bits = block_size * 8;
3,372,004✔
1030

1031
               if constexpr(is_byte_aligned()) {
1032
                  auto sink = m_source.as_byte_span().subspan(write_bytepos()).template first<block_size>();
3,345,691✔
1033
                  store_le(sink, block);
3,345,691✔
1034
               } else {
1035
                  const size_type byte_pos = write_bytepos();
26,313✔
1036
                  const size_type bits_to_store = std::min(block_bits, bits_to_write());
52,626✔
1037

1038
                  uint8_t& first_byte = m_source.as_byte_span()[byte_pos];
26,313✔
1039

1040
                  // Set the left-most bits in the first byte, leaving all others unchanged
1041
                  first_byte = (first_byte & uint8_t(0xFF >> m_unaligned_helper.bits_to_byte_alignment)) |
26,313✔
1042
                               uint8_t(block << m_unaligned_helper.padding_bits);
26,313✔
1043

1044
                  // If more bits are provided, we store them in the remaining bytes.
1045
                  if(m_unaligned_helper.bits_to_byte_alignment < bits_to_store) {
26,313✔
1046
                     const auto remaining_bytes =
1047
                        m_source.as_byte_span().subspan(byte_pos + 1).template first<block_size>();
26,313✔
1048
                     const BlockT padding_mask = ~(BlockT(-1) >> m_unaligned_helper.bits_to_byte_alignment);
26,313✔
1049
                     const BlockT new_bytes =
26,313✔
1050
                        (load_le(remaining_bytes) & padding_mask) | block >> m_unaligned_helper.bits_to_byte_alignment;
26,313✔
1051
                     store_le(remaining_bytes, new_bytes);
26,313✔
1052
                  }
1053
               }
1054

1055
               m_write_bitpos += std::min(block_bits, bits_to_write());
3,372,004✔
1056
            }
3,372,004✔
1057

1058
            template <std::unsigned_integral BlockT>
1059
               requires(is_byte_aligned() && !is_const())
1060
            std::span<BlockT> span(size_type blocks) const {
1,180,219,059✔
1061
               BOTAN_DEBUG_ASSERT(blocks == 0 || is_memory_aligned_to<BlockT>());
1,180,219,059✔
1062
               BOTAN_DEBUG_ASSERT(read_bytepos() % sizeof(BlockT) == 0);
1,180,219,059✔
1063
               // Intermittently casting to void* to avoid a compiler warning
1064
               void* ptr = reinterpret_cast<void*>(m_source.as_byte_span().data() + read_bytepos());
1,180,219,059✔
1065
               return {reinterpret_cast<BlockT*>(ptr), blocks};
1,180,219,059✔
1066
            }
1067

1068
            template <std::unsigned_integral BlockT>
1069
               requires(is_byte_aligned() && is_const())
1070
            std::span<const BlockT> span(size_type blocks) const {
1,180,431,259✔
1071
               BOTAN_DEBUG_ASSERT(blocks == 0 || is_memory_aligned_to<BlockT>());
1,180,431,259✔
1072
               BOTAN_DEBUG_ASSERT(read_bytepos() % sizeof(BlockT) == 0);
1,180,431,259✔
1073
               // Intermittently casting to void* to avoid a compiler warning
1074
               const void* ptr = reinterpret_cast<const void*>(m_source.as_byte_span().data() + read_bytepos());
1,180,431,259✔
1075
               return {reinterpret_cast<const BlockT*>(ptr), blocks};
1,180,431,259✔
1076
            }
1077

1078
            void advance(size_type bytes)
1,180,431,292✔
1079
               requires(is_byte_aligned())
1080
            {
1081
               m_read_bitpos += bytes * 8;
1,180,431,292✔
1082
               m_write_bitpos += bytes * 8;
1,180,431,292✔
1083
            }
1084

1085
            template <std::unsigned_integral BlockT>
1086
               requires(is_byte_aligned())
1087
            size_t is_memory_aligned_to() const {
786,883,455✔
1088
               const void* cptr = m_source.as_byte_span().data() + read_bytepos();
786,883,455✔
1089
               const void* ptr_before = cptr;
786,883,455✔
1090

1091
               // std::align takes `ptr` as a reference (!), i.e. `void*&` and
1092
               // uses it as an out-param. Though, `cptr` is const because this
1093
               // method is const-qualified, hence the const_cast<>.
1094
               void* ptr = const_cast<void*>(cptr);
786,883,455✔
1095
               size_t size = sizeof(BlockT);
786,883,455✔
1096
               return ptr_before != nullptr && std::align(alignof(BlockT), size, ptr, size) == ptr_before;
1,573,766,910✔
1097
            }
1098

1099
         private:
1100
            size_type read_bytepos() const { return m_read_bitpos / 8; }
793,646,051✔
1101

1102
            size_type write_bytepos() const { return m_write_bitpos / 8; }
3,372,004✔
1103

1104
         private:
1105
            BitvectorT& m_source;
1106
            size_type m_start_bitoffset;
1107
            size_type m_bitlength;
1108

1109
            UnalignedDataHelper m_unaligned_helper;
1110

1111
            mutable size_type m_read_bitpos;
1112
            mutable size_type m_write_bitpos;
1113
      };
1114

1115
      /**
1116
       * Helper struct for the low-level handling of blockwise operations
1117
       *
1118
       * This has two main code paths: Optimized for byte-aligned ranges that
1119
       * can simply be taken from memory as-is. And a generic implementation
1120
       * that must assemble blocks from unaligned bits before processing.
1121
       */
1122
      template <typename FnT, typename... ParamTs>
1123
         requires detail::blockwise_processing_callback<FnT, ParamTs...>
1124
      class blockwise_processing_callback_trait {
1125
         public:
1126
            constexpr static bool needs_mask = detail::blockwise_processing_callback_with_mask<FnT, ParamTs...>;
1127
            constexpr static bool is_manipulator = detail::manipulating_blockwise_processing_callback<FnT, ParamTs...>;
1128
            constexpr static bool is_predicate = detail::predicate_blockwise_processing_callback<FnT, ParamTs...>;
1129
            static_assert(!is_manipulator || !is_predicate, "cannot be manipulator and predicate at the same time");
1130

1131
            /**
1132
             * Applies @p fn to the blocks provided in @p blocks by simply reading from
1133
             * memory without re-arranging any bits across byte-boundaries.
1134
             */
1135
            template <std::unsigned_integral... BlockTs>
1136
               requires(all_same_v<std::remove_cv_t<BlockTs>...> && sizeof...(BlockTs) == sizeof...(ParamTs))
1137
            constexpr static bool apply_on_full_blocks(FnT fn, std::span<BlockTs>... blocks) {
1,180,431,292✔
1138
               constexpr size_type bits = sizeof(detail::first_t<BlockTs...>) * 8;
1,180,431,292✔
1139
               const size_type iterations = detail::first(blocks...).size();
1,180,219,401✔
1140
               for(size_type i = 0; i < iterations; ++i) {
2,147,483,647✔
1141
                  if constexpr(is_predicate) {
1142
                     if(!apply(fn, bits, blocks[i]...)) {
33✔
1143
                        return false;
1144
                     }
1145
                  } else if constexpr(is_manipulator) {
1146
                     detail::first(blocks...)[i] = apply(fn, bits, blocks[i]...);
2,147,483,647✔
1147
                  } else {
1148
                     apply(fn, bits, blocks[i]...);
5,792,403✔
1149
                  }
1150
               }
1151
               return true;
375✔
1152
            }
1153

1154
            /**
1155
             * Applies @p fn to as many blocks as @p ops provide for the given type.
1156
             */
1157
            template <std::unsigned_integral BlockT, typename... BitRangeOperatorTs>
1158
               requires(sizeof...(BitRangeOperatorTs) == sizeof...(ParamTs))
1159
            constexpr static bool apply_on_unaligned_blocks(FnT fn, BitRangeOperatorTs&... ops) {
393,842,351✔
1160
               constexpr size_type block_bits = sizeof(BlockT) * 8;
393,842,351✔
1161
               auto bits = detail::first(ops...).bits_to_read();
393,842,351✔
1162
               if(bits == 0) {
393,842,351✔
1163
                  return true;
1164
               }
1165

1166
               bits += block_bits;  // avoid unsigned integer underflow in the following loop
244,628✔
1167
               while(bits > block_bits * 2 - 8) {
3,661,545✔
1168
                  bits -= block_bits;
3,416,918✔
1169
                  if constexpr(is_predicate) {
1170
                     if(!apply(fn, bits, ops.template load_next<BlockT>()...)) {
21✔
1171
                        return false;
1172
                     }
1173
                  } else if constexpr(is_manipulator) {
1174
                     detail::first(ops...).store_next(apply(fn, bits, ops.template load_next<BlockT>()...));
3,410,694✔
1175
                  } else {
1176
                     apply(fn, bits, ops.template load_next<BlockT>()...);
44,900✔
1177
                  }
1178
               }
1179
               return true;
1180
            }
1181

1182
         private:
1183
            template <std::unsigned_integral... BlockTs>
1184
               requires(all_same_v<BlockTs...>)
1185
            constexpr static auto apply(FnT fn, size_type bits, BlockTs... blocks) {
2,147,483,647✔
1186
               if constexpr(needs_mask) {
1187
                  return fn(blocks..., make_mask<detail::first_t<BlockTs...>>(bits));
3✔
1188
               } else {
1189
                  return fn(blocks...);
2,147,483,647✔
1190
               }
1191
            }
1192
      };
1193

1194
      /**
1195
       * Helper function of `full_range_operation` and `range_operation` that
1196
       * calls @p fn on a given aligned unsigned integer block as long as the
1197
       * underlying bit range contains enough bits to fill the block fully.
1198
       *
1199
       * This uses bare memory access to gain a speed up for aligned data.
1200
       */
1201
      template <std::unsigned_integral BlockT, typename FnT, typename... BitRangeOperatorTs>
1202
         requires(detail::blockwise_processing_callback<FnT, BitRangeOperatorTs...> &&
1203
                  sizeof...(BitRangeOperatorTs) > 0)
1204
      static bool _process_in_fully_aligned_blocks_of(FnT fn, BitRangeOperatorTs&... ops) {
1,180,431,292✔
1205
         constexpr size_type block_bytes = sizeof(BlockT);
1,180,431,292✔
1206
         constexpr size_type block_bits = block_bytes * 8;
1,180,431,292✔
1207
         const size_type blocks = detail::first(ops...).bits_to_read() / block_bits;
1,180,431,292✔
1208

1209
         using callback_trait = blockwise_processing_callback_trait<FnT, BitRangeOperatorTs...>;
1210
         const auto result = callback_trait::apply_on_full_blocks(fn, ops.template span<BlockT>(blocks)...);
2,147,483,647✔
1211
         (ops.advance(block_bytes * blocks), ...);
1,180,431,292✔
1212
         return result;
1,180,431,292✔
1213
      }
1214

1215
      /**
1216
       * Helper function of `full_range_operation` and `range_operation` that
1217
       * calls @p fn on a given unsigned integer block size as long as the
1218
       * underlying bit range contains enough bits to fill the block.
1219
       */
1220
      template <std::unsigned_integral BlockT, typename FnT, typename... BitRangeOperatorTs>
1221
         requires(detail::blockwise_processing_callback<FnT, BitRangeOperatorTs...>)
1222
      static bool _process_in_unaligned_blocks_of(FnT fn, BitRangeOperatorTs&... ops) {
393,842,351✔
1223
         using callback_trait = blockwise_processing_callback_trait<FnT, BitRangeOperatorTs...>;
1224
         return callback_trait::template apply_on_unaligned_blocks<BlockT>(fn, ops...);
393,751,036✔
1225
      }
1226

1227
      /**
1228
       * Apply @p fn to all bits in the ranges defined by @p ops. If more than
1229
       * one range operator is passed to @p ops, @p fn receives corresponding
1230
       * blocks of bits from each operator. Therefore, all @p ops have to define
1231
       * the exact same length of their underlying ranges.
1232
       *
1233
       * @p fn may return a bit block that will be stored into the _first_ bit
1234
       * range passed into @p ops. If @p fn returns a boolean, and its value is
1235
       * `false`, the range operation is cancelled and `false` is returned.
1236
       *
1237
       * The implementation ensures to pull bits in the largest bit blocks
1238
       * possible and reverts to smaller bit blocks only when needed.
1239
       */
1240
      template <typename FnT, typename... BitRangeOperatorTs>
1241
         requires(detail::blockwise_processing_callback<FnT, BitRangeOperatorTs...> &&
1242
                  sizeof...(BitRangeOperatorTs) > 0)
1243
      static bool range_operation(FnT fn, BitRangeOperatorTs... ops) {
393,568,420✔
1244
         BOTAN_ASSERT(has_equal_lengths(ops...), "all BitRangeOperators have the same length");
162,070✔
1245

1246
         if constexpr((BitRangeOperatorTs::is_byte_aligned() && ...)) {
1247
            // Note: At the moment we can assume that this will always be used
1248
            //       on the _entire_ bitvector. Therefore, we can safely assume
1249
            //       that the bitvectors' underlying buffers are properly aligned.
1250
            //       If this assumption changes, we need to add further handling
1251
            //       to process a byte padding at the beginning of the bitvector
1252
            //       until a memory alignment boundary is reached.
1253
            const bool alignment = (ops.template is_memory_aligned_to<uint64_t>() && ...);
786,883,455✔
1254
            BOTAN_ASSERT_NOMSG(alignment);
×
1255

1256
            return _process_in_fully_aligned_blocks_of<uint64_t>(fn, ops...) &&
786,954,200✔
1257
                   _process_in_fully_aligned_blocks_of<uint32_t>(fn, ops...) &&
786,954,187✔
1258
                   _process_in_fully_aligned_blocks_of<uint16_t>(fn, ops...) &&
786,954,197✔
1259
                   _process_in_unaligned_blocks_of<uint8_t>(fn, ops...);
393,477,091✔
1260
         } else {
1261
            return _process_in_unaligned_blocks_of<uint64_t>(fn, ops...) &&
182,630✔
1262
                   _process_in_unaligned_blocks_of<uint32_t>(fn, ops...) &&
91,315✔
1263
                   _process_in_unaligned_blocks_of<uint16_t>(fn, ops...) &&
182,630✔
1264
                   _process_in_unaligned_blocks_of<uint8_t>(fn, ops...);
91,315✔
1265
         }
1266
      }
1267

1268
      /**
1269
       * Apply @p fn to all bit blocks in the bitvector(s).
1270
       */
1271
      template <typename FnT, typename... BitvectorTs>
1272
         requires(detail::blockwise_processing_callback<FnT, BitvectorTs...> &&
1273
                  (is_bitvector_v<std::remove_cvref_t<BitvectorTs>> && ... && true))
1274
      static bool full_range_operation(FnT&& fn, BitvectorTs&... bitvecs) {
393,477,105✔
1275
         BOTAN_ASSERT(has_equal_lengths(bitvecs...), "all bitvectors have the same length");
393,477,105✔
1276
         return range_operation(std::forward<FnT>(fn), BitRangeOperator<BitvectorTs>(bitvecs)...);
393,477,105✔
1277
      }
1278

1279
      template <typename SomeT, typename... SomeTs>
1280
      static bool has_equal_lengths(const SomeT& v, const SomeTs&... vs) {
786,851,394✔
1281
         return ((v.size() == vs.size()) && ... && true);
786,851,394✔
1282
      }
1283

1284
      template <std::unsigned_integral T>
1285
      static constexpr T make_mask(size_type bits) {
3✔
1286
         const bool max = bits >= sizeof(T) * 8;
3✔
1287
         bits &= T(max - 1);
3✔
1288
         return (T(!max) << bits) - 1;
3✔
1289
      }
1290

1291
      auto as_byte_span() { return std::span{m_blocks.data(), m_blocks.size() * sizeof(block_type)}; }
1,580,369,414✔
1292

1293
      auto as_byte_span() const { return std::span{m_blocks.data(), m_blocks.size() * sizeof(block_type)}; }
1,577,298,959✔
1294

1295
   private:
1296
      size_type m_bits;
1297
      std::vector<block_type, allocator_type> m_blocks;
1298
};
1299

1300
using secure_bitvector = bitvector_base<secure_allocator>;
1301
using bitvector = bitvector_base<std::allocator>;
1302

1303
namespace detail {
1304

1305
/**
1306
 * If one of the allocators is a Botan::secure_allocator, this will always
1307
 * prefer it. Otherwise, the allocator of @p lhs will be used as a default.
1308
 */
1309
template <bitvectorish T1, bitvectorish T2>
1310
constexpr auto copy_lhs_allocator_aware(const T1& lhs, const T2&) {
60✔
1311
   constexpr bool needs_secure_allocator =
60✔
1312
      strong_type_wrapped_type<T1>::uses_secure_allocator || strong_type_wrapped_type<T2>::uses_secure_allocator;
1313

1314
   if constexpr(needs_secure_allocator) {
1315
      return lhs.template as<secure_bitvector>();
56✔
1316
   } else {
1317
      return lhs.template as<bitvector>();
5✔
1318
   }
1319
}
1320

1321
}  // namespace detail
1322

1323
template <bitvectorish T1, bitvectorish T2>
1324
auto operator|(const T1& lhs, const T2& rhs) {
4✔
1325
   auto res = detail::copy_lhs_allocator_aware(lhs, rhs);
4✔
1326
   res |= rhs;
4✔
1327
   return res;
4✔
1328
}
×
1329

1330
template <bitvectorish T1, bitvectorish T2>
1331
auto operator&(const T1& lhs, const T2& rhs) {
3✔
1332
   auto res = detail::copy_lhs_allocator_aware(lhs, rhs);
3✔
1333
   res &= rhs;
3✔
1334
   return res;
3✔
1335
}
×
1336

1337
template <bitvectorish T1, bitvectorish T2>
1338
auto operator^(const T1& lhs, const T2& rhs) {
53✔
1339
   auto res = detail::copy_lhs_allocator_aware(lhs, rhs);
53✔
1340
   res ^= rhs;
53✔
1341
   return res;
53✔
1342
}
×
1343

1344
template <bitvectorish T1, bitvectorish T2>
1345
bool operator==(const T1& lhs, const T2& rhs) {
6✔
1346
   return lhs.equals_vartime(rhs);
6✔
1347
}
1348

1349
template <bitvectorish T1, bitvectorish T2>
1350
bool operator!=(const T1& lhs, const T2& rhs) {
1351
   return lhs.equals_vartime(rhs);
1352
}
1353

1354
namespace detail {
1355

1356
/**
1357
 * A Strong<> adapter for arbitrarily large bitvectors
1358
 */
1359
template <concepts::container T>
1360
   requires is_bitvector_v<T>
1361
class Strong_Adapter<T> : public Container_Strong_Adapter_Base<T> {
521,202✔
1362
   public:
1363
      using size_type = typename T::size_type;
1364

1365
   public:
1366
      using Container_Strong_Adapter_Base<T>::Container_Strong_Adapter_Base;
485✔
1367

1368
      auto at(size_type i) const { return this->get().at(i); }
51,200✔
1369

1370
      auto at(size_type i) { return this->get().at(i); }
389,450,340✔
1371

1372
      auto set(size_type i) { return this->get().set(i); }
1✔
1373

1374
      auto unset(size_type i) { return this->get().unset(i); }
1✔
1375

1376
      auto flip(size_type i) { return this->get().flip(i); }
1✔
1377

1378
      auto flip() { return this->get().flip(); }
1✔
1379

1380
      template <typename OutT>
1381
      auto as() const {
53✔
1382
         return this->get().template as<OutT>();
53✔
1383
      }
1384

1385
      template <bitvectorish OutT = T>
1386
      auto subvector(size_type pos, std::optional<size_type> length = std::nullopt) const {
119,028✔
1387
         return this->get().template subvector<OutT>(pos, length);
118,980✔
1388
      }
1389

1390
      template <typename OutT>
1391
         requires(std::unsigned_integral<strong_type_wrapped_type<OutT>> &&
1392
                  !std::same_as<bool, strong_type_wrapped_type<OutT>>)
1393
      auto subvector(size_type pos) const {
65,724✔
1394
         return this->get().template subvector<OutT>(pos);
65,724✔
1395
      }
1396

1397
      template <typename InT>
1398
         requires(std::unsigned_integral<strong_type_wrapped_type<InT>> && !std::same_as<bool, InT>)
1399
      void subvector_replace(size_type pos, InT value) {
65,723✔
1400
         return this->get().subvector_replace(pos, value);
65,723✔
1401
      }
1402

1403
      template <bitvectorish OtherT>
1404
      auto equals(const OtherT& other) const {
45✔
1405
         return this->get().equals(other);
45✔
1406
      }
1407

1408
      auto push_back(bool b) { return this->get().push_back(b); }
327,521✔
1409

1410
      auto pop_back() { return this->get().pop_back(); }
2✔
1411

1412
      auto front() const { return this->get().front(); }
1413

1414
      auto front() { return this->get().front(); }
1✔
1415

1416
      auto back() const { return this->get().back(); }
1417

1418
      auto back() { return this->get().back(); }
1✔
1419

1420
      auto any_vartime() const { return this->get().any_vartime(); }
1✔
1421

1422
      auto all_vartime() const { return this->get().all_vartime(); }
1✔
1423

1424
      auto none_vartime() const { return this->get().none_vartime(); }
1✔
1425

1426
      auto has_odd_hamming_weight() const { return this->get().has_odd_hamming_weight(); }
1✔
1427

1428
      auto hamming_weight() const { return this->get().hamming_weight(); }
53✔
1429

1430
      auto from_bytes(std::span<const uint8_t> bytes, std::optional<size_type> bits = std::nullopt) {
1431
         return this->get().from_bytes(bytes, bits);
1432
      }
1433

1434
      template <typename OutT = T>
1435
      auto to_bytes() const {
1436
         return this->get().template to_bytes<OutT>();
1437
      }
1438

1439
      auto to_bytes(std::span<uint8_t> out) const { return this->get().to_bytes(out); }
48✔
1440

1441
      auto to_string() const { return this->get().to_string(); }
1✔
1442

1443
      auto capacity() const { return this->get().capacity(); }
1444

1445
      auto reserve(size_type n) { return this->get().reserve(n); }
1446

1447
      constexpr void _const_time_poison() const { this->get()._const_time_poison(); }
51✔
1448

1449
      constexpr void _const_time_unpoison() const { this->get()._const_time_unpoison(); }
86✔
1450
};
1451

1452
}  // namespace detail
1453

1454
}  // namespace Botan
1455

1456
#endif
STATUS · Troubleshooting · Open an Issue · Sales · Support · CAREERS · ENTERPRISE · START FREE · SCHEDULE DEMO
ANNOUNCEMENTS · TWITTER · TOS & SLA · Supported CI Services · What's a CI service? · Automated Testing

© 2026 Coveralls, Inc